by Aamer Madhani, USA TODAY

by Aamer Madhani, USA TODAY

WASHINGTON-President Obama said Tuesday that his administration would re-engage Congress on closing the U.S. military-run detention center at Guantanamo Bay, calling the facility a "recruitment tool for extremists" and suggesting it is undermining U.S. security.

"It needs to be closed," Obama said at a White House news conference marking the first 100 days of his second term. "I'm going to go back at this."

Obama's comments come as military officials say that as many as 100 prisoners at Guantanamo are engaged in a hunger strike.

With the situation getting more difficult, the Pentagon in recent days dispatched 40 additional Navy medical personnel to Guantanamo to deal with the hunger strikers. They bolstered a staff of about 100, said Lt. Col. Samuel House, a detention camp spokesman.

Obama had vowed in his 2008 presidential campaign to close Guantanamo during his first year in office but failed to get it done in his first term.

"It' is not a surprise to me that we are having problems in Guantanamo," Obama said. Obama called Guantanamo unsafe and expensive and said it lessens cooperation with U.S. allies.

He noted that Congress has legislatively blocked him from closing Guantanamo--lawmakers have attached provisions to military spending bills that bar the administration from spending on trials for Guantanamo detainees and early in his presidency his administration faced stiff opposition to a plan to transfer detainees to a facility in Illinois

On Tuesday, the president offered no solution to getting around congressional hurdles.

Rep. Buck McKeon, R-Calif., chairman of the House Armed Services Committee, took issue with Obama's charge that Congress has blocked him from closing Guantanamo.

"The President faces bipartisan opposition to closing Guantanamo Bay's detention center because he has offered no alternative plan regarding the detainees there, nor a plan for future terrorist captures," McKeon said in a statement.

Advocates of closing Guantanamo say there are two important steps Obama can take toward his end goal--wresting control of his closure policy from the Pentagon and directing Defense Secretary Chuck Hagel to start certifying for transfer detainees who have already been cleared for transfer--more than half the prison's population--but continue to be held at the detention center in Cuba.

"There's more to be done, but these are the two essential first steps the president can take now to break the Guantanamo logjam," said Anthony Romero, the American Civil Liberties Union executive director.

Eighty-six Guantanamo prisoners were cleared for release more than three years ago. Most of them are from Yemen, but Obama halted transfers to that country following a failed attempted by a Nigerian man to blow up a Detroit-bound flight on Christmas Day 2009. The assailant had ties to the Yemen-based Al Qaeda in the Arabian Peninsula.

Last week, Sen. Dianne Feinstein, chairman of the Senate Intelligence Committee, wrote to National Security Council Adviser Tom Donilon that it was time to reconsider the status of those 86 prisoners.

"The fact that so many detainees have now been held at Guantanamo for over a decade and their belief that there is still no end in sight for them is a reason there is a growing problem of more and more detainees on a hunger strike," Feinstein wrote.

On Tuesday, Obama agreed that Guantanamo might have been seen as necessary after the Sept. 11 attacks. But the president said the time to close the prison for high-value terror suspects who were captured on foreign soil is now.

"The idea that we would still maintain forever a group of individuals who have not been tried, that is contrary to who we are, it is contrary to our interests, and it needs to stop," Obama said.

Obama also appeared to defend the Defense Department's decision to force feed the striking prisoners."I don't want these individuals to die," he said.

Meanwhile, Obama addressed intelligence reports that show chemical weapons were likely deployed in Syria. He said it would be a "game-changer" if it is confirmed that Syria's President Bashar Assad used chemical weapons on his people.

But when pressed on whether confirmation would mean military action, the president said that it only means that his administration would have to rethink its options.

"We don't know how they were used, when they were used, who used them.," Obama said. "And when I am making decisions about America's national security and the potential for taking additional action in response to chemical weapon use, I've got to make sure I've got the facts."

Obama had previously drawn a "red line" on the use or transfer of chemical weapons by Assad's regime.

Obama said that taking additional action without hard evidence could compromise the U. S. position internationally.

"If we end up rushing to judgment without hard, effective evidence, then we can find ourselves where we can't mobilize the international community to support what we do," Obama said.

But Obama stressed that if it is confirmed that the Assad regime has used chemical weapons, his administration would take new action.

Obama also pushed back against criticism from some GOP lawmakers that have suggested that the FBI dropped the ball when the Russian government asked it to investigate one of the Boston bombing suspects, Tamerlan Tsarnaev, in 2011.

"Based on what I've seen so far, the FBI performed its duties, the Department of Homeland Security did what it was supposed to be doing," Obama said. "But this is hard stuff."

In other developments, Obama commented about Jason Collins, the NBA player who became the first active athlete in major league sports to come out as gay. Obama said he spoke to Collins on Monday and called him "a terrific young man."

"I told him that I could not be prouder of him," Obama said.

Obama also responded to criticism about his inability to get the Senate to pass legislation to enhance background checks in the aftermath of last year's school shooting in Newtown, Conn., which left 20 small children and six educators dead.

Asked whether he had "any juice" left to get anything done in Washington, Obama responded jokingly that it sounded like he "should just pack up and go home."